title: PLP inhibits the activity of interphase centrosomes to ensure their proper segregation in stem cells.
abstract: Centrosomes determine the mitotic axis of asymmetrically dividing stem cells. Several studies have shown that the centrosomes of the Drosophila melanogaster central brain neural stem cells are themselves asymmetric, organizing varying levels of pericentriolar material and microtubules. This asymmetry produces one active and one inactive centrosome during interphase. We identify pericentrin-like protein (PLP) as a negative regulator of centrosome maturation and activity. We show that PLP is enriched on the inactive interphase centrosome, where it blocks recruitment of the master regulator of centrosome maturation, Polo kinase. Furthermore, we find that ectopic Centrobin expression influenced PLP levels on the basal centrosome, suggesting it may normally function to regulate PLP. Finally, we conclude that, although asymmetric centrosome maturation is not required for asymmetric cell division, it is required for proper centrosome segregation to the two daughter cells.
authors.affiliation: Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892.
authors.forename: Dorothy A
authors.initials: DA
authors.lastname: Lerit
authors.forename: Nasser M
authors.initials: NM
authors.lastname: Rusan
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001921:Brain / Q000166:cytology / Q000378:metabolism; D002148:Calmodulin-Binding Proteins; D018385:Centrosome / Q000378:metabolism*; D020090:Chromosome Segregation / Q000235:genetics*; D029721:Drosophila Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D007091:Image Processing, Computer-Assisted; D007399:Interphase / Q000235:genetics*; D008938:Mitosis / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D008941:Spindle Apparatus; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism
chemical_list: D002148:Calmodulin-Binding Proteins; D029721:Drosophila Proteins; C483309:Plp protein, Drosophila; C072004:polo protein, Drosophila; D017346:Protein Serine-Threonine Kinases